Thursday, September 24, 2009

Lunar Weather: many miles wide, 2 mm deep

Chart highlighting the calibration observations by Deep Impact of the northern polar regions of the moon on June 9. At left is a reference albedo map from Clementine while the other images are different representations of Deep Impact data, including measurements of brightness, temperature, and the strength of a signature for water and hydroxyl. The water signature varies significantly across the lunar surface but, while the strength of the water signature is not correlated with any terrain type it is highly dependent on temperature. Since successfully carrying out a spectacular impact experiment on comet Tempel 1 July 4, 2005, Deep Impact spacecraft has been on an extended mission, called "EPOXI," which will culminate in a flyby of comet Hartley 2 on November 4 2010. The spacecraft observed the moon for calibration purposes on several occasions en route to its second cometary encounter. [NASA/JPL-Caltech/University of Maryland]